net/mlx4_en: Use access helper irq_data_get_affinity_mask()

This is a preparatory patch for moving irq_data struct members. Search
and replace was done with coccinelle

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Amir Vadai <amirv@mellanox.com>